Steel coating by self-induced ion plating, a new high throughput metallization ion plating technique

Abstract

Ion plating techniques present major advantages for continuous steel coating in terms of throughput and product quality when compared, respectively, to sputtering and vacuum evaporation techniques. However, the ion plating systems available on the market today are cumbersome and have technological problems that prevent immediate implementation in high throughput air-to-air continuous steel coating plants. To address these problems, we have developed a new ion plating technique, referred to as “self-induced ion plating,” in order to produce continuous coating on flat products. This technique is based on the generation of a magnetron discharge in the sputtered and evaporated vapor produced by a tin cylindrical target. Very high deposition rates were achieved (⩽220 μm/min) with moderate values of the electrical mean power density (⩽45 W cm−2) applied to the tin target. The magnetron configuration reduced material side losses by reducing the metal escape zone area on the target side. Another feature of this technique is that the control of the heat transfer between the target and its backing plate allows control of the target surface temperature, and hence control of the sputtered and evaporated material fractions.